This invention is directed to a device for protecting the user, commonly the phlebotomist, from becoming pricked by the needle when removing it from a blood drawing instrument, which needle might have become contaminated in a venipuncturing process. A device of this general nature is known from our co-pending application, Ser. No. 07/512,466, filed Apr. 23, 1990. The present invention, however, varies from the subject of our co-pending application in that it is directed primarily to camming means of a nature for holding the needle fast against relative movement after it has been unsheathed, so as to enable the instrument to be unthreaded from the needle.
Generally, a syringe or an evacuated tube type instrument is employed in venipuncturing to obtain blood test samples. Many phlebotomists prefer to use the evacuated tube type instrument for this purpose. This instrument includes a barrel that is open at both ends. A double ended needle is adapted to be engaged in a front end of the barrel in a manner in which one end of the needle extends into the barrel and the other end projects from the barrel. The needle has a hub intermediately of its ends. A rear portion of the hub is threaded and is adapted to be engaged with complementary threads in the barrel. And a forward portion of the hub has straight splines with which complimentary splines of a protective sheath disposed over the external portion of the needle are slidably engaged. And the barrel has an open rear end into which a rubber stoppered evacuated tube is adapted in use of the instrument to be slidably entered to be punctured by the portion of the needle within the barrel.
In making use of the evacuated tube type instrument, it is customary for the phlebotomist to remove the sheath from the needle by hand. He does this by holding the barrel in one hand and pulling the sheath from the needle with the other hand. At this time the unused needle is sterile. Accordingly, the phlebotomist is normally safe from becoming infected if he should become accidentally pricked by the needle when removing the sheath.
But, after the instrument has been used for blood drawing, the needle may have become contaminated. It is then that the phlebotomist must be extra careful in removing the used needle from the instrument to avoid being pricked and possibly infected. With this danger being ever present, the device embodying the present invention has been designed to enable the phlebotomist to safely effect removal of the needle by means of the device and not by hand.
Accordingly, a general object of this invention is to provide a device which will enable the phlebotomist to effect removal of a used needle from a venipuncturing instrument without risk of becoming pricked by the needle and without his manually contacting the needle in effecting its removal.
A further object of the invention is to provide a device into which the needle end of a conventional venipuncturing instrument may be entered and held so as to allow the body of the instrument to be threadly disconnected from the needle and to allow the disconnected needle to drop through the device into a disposable container below.
A more particular object of the invention is to provide a device into which the unsheathed needle of a venipuncturing instrument of the evacuated tube type may be inserted and cammed against movement so as to enable the user to apply a twisting force to the barrel of the instrument to effect unthreading and separation of the barrel from the needle, and which device includes a disposable container at its bottom into which the needle when disconnected from the instrument will drop upon release of its cammed condition.
An advantageous feature of the invention is a cam element in the device which is pivotable under load of a spring to obtain an interlocked condition with a splined portion of an unsheathed needle of a venipuncturing instrument inserted into a passage of the device, whereby the body of the instrument may be unthreaded from the needle and the disconnected needle will upon subsequent manual pivoting of the cam element out of the interlocked condition against the spring load drop out of the passage into a disposable container.
Another desirable feature of the invention is provided by a spring which is engaged to an arm portion of the cam element and serves to normally bias the cam element so as to provide a holding force of the cam element upon a needle inserted into a passage of the device and thereby enable the body of an associated instrument to be unthreaded from the needle.
While the device of the invention is of particular advantage to the user in effecting for him a safe and protected disengagement and disposal of the unsheathed used needle from a venipuncturing instrument without the user manually touching the needle, the device may also be used for removing and disposing of the sheath from the needle preparatory to use of the instrument.
The invention further lies in its particular structure and in the arrangement of its components as well as in their mode of cooperation with one another to effect the objectives and various advantages intended for it.